Posted 22 hours ago,
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in collaboration with
Dr Gérald Kierzek (Medical Director of Doctissimo)
Two new strains of the Omicron variant, the BA.4 and BA.5 sub-variants, have been detected on French soil. Responsible for several waves of contamination, they are subject to increased surveillance.
While the number of Covid-19 contaminations continues to climb, two new variants have just been detected in France: BA.4 and BA.5. Discovered in South Africa, last December and January, where they are responsible for an explosion of cases in the country (70% of sequenced strains), they present additional mutations, raising fears of an increase in their transmissibility.
On French soil, their presence is still minimal according to the National Public Health Agency: “As of April 21, one case of BA.4 and two cases of BA.5 have been identified in France“.
BA.4 and BA.5 have two “mutations of interest”
Like the Omicron variant, BA.4 and BA.5 have been classified as “variants of interest” by the World Health Organization (WHO). They have been detected in more than twenty countries such as Botswana, Australia, China, England and Denmark.
The F486 mutation would be associated with a reduction in the neutralization of antibodies. In other words: vaccine efficacy would be likely to decrease. As for the L452R mutation, it would allow the virus to infect human cells more easily.
“We may therefore be dealing with a more transmissible variant than Omicron and escaping acquired and vaccinal immunity, but not necessarily with a strain associated with greater severity”explains Antoine Flahault, medical epidemiologist and director of the Institute for Global Health at the University of Geneva, to “La Dépêche du Midi”.
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More transmissible and more resistant to vaccines
This means that BA.4 and BA.5 are likely to be resistant to vaccines and more transmissible than Omicron. But these sub-variants would not however be more dangerous.
“Certainly, new variants appear, but it is the natural life of a virus. Its objective is to survive and therefore to vary, but it is not necessarily more dangerous. We’re going to have to learn to live with it everywhere, all the time.”points out Dr. Kierzek.
For the moment, no new wave is on the agenda in France and Europe because “no worrying epidemiological or clinical element is associated with them“, attests the National Public Health Agency.
In the United States, another sub-sub-variant of Omicron worries the authorities – the BA.2.12.1 – at the origin of an increase in contaminations in the State.